Parc Floral de Paris

"At 2,500 acres (about three times the size of NYC's Central Park) the Bois de Vincennes was ample enough to act as the royal hunting grounds in the 13th and 14th centuries, and serve as the site of most of the events during the 1900 Summer Olympics. 17 years later, Dutch spy Mata Hari would be executed in the park's fortress. But we digress: The Bois de Vincenne's Parc Floral de Paris is one of four botanical gardens in the city, home to 3,000 types of plant (including 650 varieties of Iris). There are peacocks, there's a bonsai garden, and there's an annual jazz festival in the park's amphitheater that draws big crowds."